Display tube

ABSTRACT

In the present invention, a display tube for displaying a plurality of characters including a plurality of individual electron beam sources that are provided within the tube envelope. Each of the sources is mechanically directed toward a common point on a fluorescent display screen. A mask having a number of shaped apertures, wherein each aperture is associated with a different source, is interposed between the sources and the display screen. A pair of deflection means for deflecting the electron beam away from a common point on the display screen is located between the mask and the screen. A control means is provided interior to the tube for sequentially changing the voltage on a particular one of the deflection means so that the display of the plurality of characters will be displayed substantially an equal distance apart from each other on the fluorescent display screen.

United States Patent 1 Gumpertz DISPLAY TUBE [75] Inventor: Donald Gumpertz, North Hollywood, Calif.

[73] Assignee: Industrial Electronic Engineers, Inc.,

Van Nuys, Calif.

[22] Filed: June 1, 1970 [21] Appl. No.: 41,844.

[52] US. Cl. 313/70, 313/109.5 [51] Int. Cl H0lj 29/70, H0lj3l/1d [58] Field of Search ..3l3/l09.5, 86 KM; 315/29,

anew/LL25 [56] References Cited UNITED STATES PATENTS 2,591,981 4/1952 Overbeek et al. 315/29 X 3,432,710 3/1969 Gumpertz 315/1095 X 3,537,097 10/1970 Gumpertz 313/70 X Primary ExaminerHerman Karl Saalbach Assistant Examiner-Richard A. Rosenberg Attorney, Agent, or Firm-Smyth, Roston and Pavitt [4 1 Feb. 19, 1974 [5 7] ABSTRACT In the present invention, a display tube for displaying a plurality of characters including a plurality of individual electron beam sources that are provided within the tube envelope. Each of the sources is mechanically directed toward a common point on a fluorescent display screen. A mask having a number of shaped apertures, wherein each aperture is associated with a different source, is interposed between the sources and the display screen. A pair of deflection means for defleeting the electron beam away from a common point on the display screen is located between the mask and the screen. A control means is provided interior to the tube for sequentially changing the voltage on a particular one of the deflection means so that the display of the plurality of characters will be displayed substantially an equal distance apart from each other on the fluorescent display screen.

19 Claims, 3 Drawing Figures DISPLAY TUBE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates in general to a display tube and more particularly to a display tube capable of providing simultaneous display of a plurality of characters on a tube display screen.

2. Description of the Prior Arts- In certain applications, it is desirable to have a display tube for conveniently converting information in the form of electrical signals to a visible, readable form. For example, such units may be employed to display the output of digital computer devices, electronic counters, and registers. The display units may be used in large multiples to make up electrically controlled annunciator panels, flight and arrival departure tables, Scoreboards, etc.

In the prior arts, a cathode ray display tube has been used that has a plurality of individual electron sources or guns located in position within the tube envelope such that each of the sources is mechanically aimed along converging axes which meet at a common point on the fluorescent display screen at the end of the tube opposite the location of the sources. lnterdisposed between the sources and the display screen is a character forming mask having a plurality of apertures therein, each of the apertures having the outline of a different one of the plurality of characters to be presented on the display screen. The number of characters in the selection corresponds to the number of electron guns provided within the tube. The mask is positioned between the guns and the display screen and the apertures are located in the mask so that each aperture is located on a different one of the source screen axes whereby energization of a particular source produces a display of a particular associated character on the display screen. The location of the mask and the size of the character forming aperture are chosen such that a stream of electrons from this selected source illuminates an aperture, forming the stream into a specific outline. The stream expands in transit toward the screen such that the image projected thereon is centered and substantially fills the screen.

Such a display tube is described in US. Pat. No. 3,432,710 titled, Display Tube Having Character Masks with Electron Gun Individual'to Each Character", in the name of Donald G. Gumpertz, filed June 8, 1967, and issued Mar. ll, 1969. The above-described display tube only provides for a single readout for a particular character at any one instant of time; however, where a multi-character readout is desired, a number of cathode ray display tubes of the type illustrated above is required corresponding to the maximum number of possible characters to be simultaneously displayed. By connecting suitable driving circuitry to the various tubes, a pre-selected one of the plurality of sources in each of the tubes is energized at any one time to produce the desired multi-charaeter readout. The cost and space required to use a separate tube for the display of each digit makes it desirable to have a single display tube capable of providing a multicharacter readout.

A cathode ray display tube has been used in the prior art that will produce a multi-character readout in one tube and comprises a vacuum tube display device for selectively presenting at least one of a selection of patterns on a screen. The display device includes an evacuated envelope having a display screen on one end, with the screen having a fluorescent coating on the interior thereof. A plurality of electron sources are located within the envelope wherein each source includes electrode means for directing a diverging stream of electrons toward the screen along the line extending from the source and passing to a common point on the screen. A means for selectively operating each of the electron sources to release a stream of electrons from a first one of said sources is connected to each one of the electrode means. A mask is provided which is located between the electron source and the screen and which is provided with openings therein in the form of selectionof patterns to be displayed. Each of the openings in the mask is aligned on a different one of the lines between the electron sources and the common point such that each source illuminates only the opening in the mask associated with the source. The display tube further includes a means for accelerating the released stream of electrons toward the mask and screen and is located between the electron sources and the mask. An

' electron stream deflection means is provided with the tube that is located intermediate with the geoemtric planes defined by the mask and the display screen for deflecting the stream of electrons away from the screen axis such that when the deflection means is energized the character projected by the device on the screen is centered on a point removed from the common point on the screen.

With the above-described prior art, a means is required external to the tube to drive the deflection means so that the characters displayed on the screen will be deflected a particular distance. The tube and the means external to the tube are disclosed and claimed in Patent application Ser. No. 695,012 filed by applicant on Jan. 2, 1968, for a Cathode Ray Display Tube. Consequently, it is desirable to have a control means interior to the tube so that the deflection means can be easily controlled from within the tube.

SUMMARY OF THE INVENTION The present invention provides a display tube for displaying a plurality of characters and includes a glass envelope having a fluorescent display screen on one end thereof. A plurality of enclosures are disposed along a filament within the glass envelope adjacent to the display screen. Each of the plurality of enclosures has an enclosure aperture therein for providing a stream of electrons toward the display screen. An electrode for accelerating the individual stream of electrons toward the display is located between the plurality of enclosures and the mask. The electrode has a plurality of electrode apertures that are in alignment with the enclosure apertures so that the streams of electrons can pass therethrough. A mask having a plurality of shaped apertures in the shape of characters to be displayed is located between the plurality of enclosures and the fluorescent display screen. Each of the plurality of shaped apertures is in alignment with a particular stream of electrons for providing an individual shaped stream of electrons to the fluorescent display screen.

A first deflection plate and a second deflection plate are disposed within the envelope that provide an electric field to the individual shaped streams of electrons for deflecting the shaped streams to a particular position on the display screen in response to the electric field. A control plate interior to the envelope and in alignment with a particular one of the plurality of enclosures is sequentially impinged by a stream of electrons for changing the voltage applied to the first and second deflection plate. The changes in voltage applied to the deflection plates causes a corresponding change in the electric field to change the position that a character will be displayed. Means are provided for impinging a stream of electrons on the control plate to progressively change the voltage between the deflection plates every time that an electron stream is directed to the display screen.

Other objects, features and advantages of the present invention will become more readily apparent with reference to the following detailed description, taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective elevation view in partial section of a character display in accordance with the prsent invention.

FIG. 2 is a block diagram of typical electrical circuitry associated with the display tube of the FIG. 1 to accomplish the purposes of the invention.

FIG. 3 is a timing diagram of electrical signals produced at strategic terminals in the circuitry shown in FIG. 2.

Referring now to the drawings wherein like reference characters designate like or corresponding parts, there is shown in FIG. I a perspective elevation view in partial section of a display tube of the present invention including an evacuated tubular glass envelope l having a first end 12 and a second end 14. A display screen 16 including a thin phosphor layer is provided on the first end 12 of the glass envelope 10. The display screen 16 provides a screen for viewing a plurality of characters I8 exterior to the tube. When the display screen 16 is impinged with a stream of electrons in the shape of at least one of the plurality of characters 18, the display screen 16 emits light in the form of a luminance in the shape of the impinging stream of electrons.

A directly heated filament 20 having a particular length is suspended between a pair of supports 22 substantially parallel to the display screen 16 for providing a source of electrons. The filament 20 is supported within an apex 24 of a triangular aperture 26 in each of a pair of supports 22. The filament 20 is connected between at least two of a plurality of leads '28 and to one of a plurality of pins 29 provided in the second end 14 of the glass envelope 10. The filament 20 is made of a suitable resistance wire or wire ribbon of the type that will produce the emission of electrons upon the application of a suitable electric current.

Disposed along the length of the filament 20 is a plurality of enclosures 30 that operate as a first cathode for providing streams of electrons in response to an applied voltage. Each of the plurality of enclosures 30 is aligned between the pair of supports 32 to provide the stream of electrons toward a fixed point substantially in the center of the display screen 16. Each of the plurality of enclosures 30 is further aligned along the length of the filament 30 so that the center of the enclosure aperture 36 is substantially the same distance from the filament 20. Alignment of each of the enclosure apertures 36 equidistant from the filament 20 has the advantage that substantially the same voltage potential is developed between each of the plurality of enclosures 30 and the filament 20 when a voltage of the same amplitude is applied thereto.

Consequently, by applying the same voltage potential between each of the shaped apertures 36 and the filament 20, each of the streams of electrons will have substantially the same electron density and velocity.

An electrode 38 or second anode having a plurality of electrode apertures 40 therein is in alignment with the plurality of enclosures 30 so that each of the electrode apertures 40 is in alignment with one of the enclosure apertures 36. The streams of electrons provided by the plurality of enclosure 30 pass through the electrode apertures 40 in the electrode 38 and toward the display screen 16. The electrode 38 has a shape in conformity with the shape of the plurality of enclosures 30 adjacent thereto. The area of the electrode 38 surrounding each of the plurality of electrode apertures 40 is substantially parallel to the area surrounding the corresponding enclosure aperture 36. When a positive voltage with respect to the voltage applied to the plurality of enclosures 30 is applied to the electrode 38, the electrode 38 will accelerate the flow of the individual streams of electrons being provided. Consequently, the individual streams of electron flow from the filament 20 through the enclosure apertures 36 in the plurality of enclosures 30, through the electrode apertures 40 in the electrode 38 toward the display screen 16 and the first end 12 of the display tube. The electrode 38 is supported between the pair 'of supports 32 and can be electrically connected to one of the plurality of tube pins 29 via one of the plurality of leads 28.

A beam shaping mask 42 is interposed in the path of the streams of electrons provided by the plurality of enclosures 30 and supported between the pair of supports 32. The beam shaping mask 42 has a plurality of shaped apertures 44 therein that are in the shape of the plurality of characters to be displayed on the display screen. The beam shaping mask 42 illustrated in FIG. I has six shaped apertures 44 in the shape of the numbers I to 6. However, it should be apparent that any shape can be used for the shaped apertures 44, such as letters, symbols, etc. and that any number of apertures may be provided, provided that a number of guns corresponding to the number of apertures is also provided.

Each of the plurality of shaped apertures 44 is in alignment with one of the electrode apertures 40 and the corresponding enclosure aperture 38 in one of the plurality of enclosures 30. The individual streams of electrons provided by the plurality of enclosures 30 passes through the electrode apertures 40 and to the shaped apertures 44 in the beam shaping mask 42. Some of the individual streams of electrons pass through the shaped apertures 44 and form a shaped stream of electrons having a shape in the shape of the particular character. The shaped stream ofelectronspasses onto the display screen 16 and impinges the display screen 16, causing the illumination of a character in the shape of the streams of electrons on the display screen 16.

A first deflection plate and a second deflection plate 52 are connected to the pair of supports 32 and in parallel relationship with each other. The first deflection plate 50 is further connected to the envelope 10 by means of a tab 54 so that a voltage may be externally applied to the first deflection plate 50. Although the first deflection plate 50 is illustrated as connected to the glass envelope by the tab 54, it could be connected externally to the glass envelope 10 by one of the plurality of pins 29 or other suitable means. The first deflection plate 50 and the second deflection plate 52 provide an electric field there between when a deflec' tion voltage is applied thereto. The electric field operates to deflect the streams of electrons from their straight line path to the display screen 16. For example, if the second deflection plate 52 is more positive than the first deflection plate 50, the streams of electrons will be drawn or deflected toward the second deflection plate 52. If the second plate 52 is made less positive than the first deflection plate 50, the streams of electrons are deflected toward the first deflection plate 50. Accordingly, the streams of electrons are deflected toward the deflection plate 50 or 52 that has the more positive voltage applied thereto.

The deflection voltage can be produced by applying a constant voltage to one of the deflection plates 50 or 52 and by applying a variable step voltage to the other one of the deflection plates 40 and 42. For example, a constant voltage, such as a voltage of 1,000 volts, can be applied to the first deflection plate 50 and variable voltage to the second deflection plate 52, such as a voltage variable between 1,100 volts and 900 volts.

Consequently, by stepwise decreasing the voltage applied to the second deflection plate 52 from a more positive voltage than the voltage applied to the first deflection plate 50 to a more negative voltage than the voltage applied to the first deflection plate 50, individual streams of electrons or characters can be sequentially deflected and represented as a series of characters on the display screen 16. The quantity of characters that can be presented is dependent only upon the size of the display screen 16 and by the number of step changes in voltage to the second deflection plate 52, and the number of enclosures within the display tube.

A control plate 60 is supported between the pair of supports 32 and is electrically coupled to the second deflection plate 52 by a lead 62. The control plate 60 is further connected to a terminal 64 by means of the lead 66. The control plate 60 is disposed above a particular one of the plurality of enclosures 30 so that the stream of electrons provided by the particular one of the enclosure 30 will impinge the control plate 60. A capacitor 68 is connected between the terminal by a ground potential. Therefore, voltage can be stored in the capacitor 68 and applied to the deflection plate 52 by applying a step pulse to the terminal 64. The voltage is stored on the capacitor 68 by impinging the control plate 60 with the stream of electrons provided by the corresponding one of the plurality of enclosures 30. The amount of discharge of the voltage on the capacitor will correspond to the length of time that the stream of electrons impinges the control plate 60. Although the capacitor 68 is shown external to the glass envelope 10, the capacitor 68 could be readily constructed within the envelope 10, between the terminal 64 and one of the plurality of tube pins 29. Consequently a positive voltage can be applied to the second deflection plate 52 which can be stepwise sequentially decreased in amplitude by applying a sequence of streams of electrons to the control plate 60.

Referring now to the operation of the display tube in more detail, to sequentially display a plurality of characters on the display screen 16, such as the numbers 246 illustrated in FIG. 2, the filament 20 is maintained at ground potential or at some constant dc voltage for providing a continuous source of electrons. Prior to displaying the first number 2, a negative or low voltage with respect to the filament 20 is applied to all of the plurality of enclosures 30. A low amplitude or negative voltage on the plurality of enclosures 30 prevents the emission of any streams of electrons therefrom. Also, a reset signal or a positive voltage is applied to the second deflection plate 52 at the terminal 64 that is more positive than a continuously positive voltage applied to the first deflection plate 50. For example, if the first deflection plate 50 is maintained at a positive 1,000 volts, the reset signal can have an amplitude of 1,100 volts. The reset signal charges the capacitor 68 to the positive voltage amplitude of the reset signal. Since there is no return path to ground from the second deflection plate 52, the voltage developed on the second deflection plate 52 and the capacitor 68 will remain substantially constant until an external source of energy is applied thereto. Therefore, the second deflection plate 52 is more positive than the first deflection plate, such as volts more positive.

To display the first character 18, for example, the number 2, a positive voltage with respect to the filament 20 is applied to the particular one of the plurality of enclosures 30 in alignment with the shaped aperture 30 having a shape of the number 2". Where the particular one of the plurality of enclosures 30 is biased positive with respect to the filament 20, a stream of electrons flo'ws through the corresponding enclosure aperture 32 toward a point at the center of the display screen 16. The stream of electrons passes through the corresponding electrode aperture 42 through a shaped aperture 30, in the shape of the integer 2, in the beam shaping mask 42 and forms a shaped stream of electrons in the shape of the number 2. As the shaped stream of electrons passes through the electric field developed between the first deflection plate 50 and the second deflection plate 52, it is deflected in the direction of the second deflection plate 52. The shaped stream of electrons impinges the display screen 16, causing an illumination of the number 2 on the display screen 16 at the end of the tube closest to the deflection plate 52.

To display the second character 18, the number 4, on the display screen 16, the enclosures 30 corresponding to the number 2 is biased negative again so that all of the plurality of enclosures are again biased negative with respect to the filament 20. Consequently, no streams of electrons are applied to the display screen 16. Subsequently, the particular one of the plurality of enclosures 30 in alignment with the discharge plate 60 is biased positive to provide a stream of electrons to the discharge plate 50. The provided stream of electrons impinge the discharge plate 60 causing the capacitor 58 and hence the discharge plate 60 to be partially discharged by a particular value. Discharging the discharge plate 60 causes a corresponding discharge of the second deflection plate 52 so that a desired new potential is produced. The amount of discharge is dependent upon the length of time that the stream of electrons impinges on the discharge plate 60. When the desired potential has been developed on the second deflection plate 52, the corresponding enclosure 30 is biased negative, causing a cessation of the stream of electrons to the discharge plate 60.

Subsequently, the particular one of the plurality of enclosures 30 corresponding to the second character 18, or the number 4, is biased positive to provide a stream of electrons to the display screen 16 as previously described. It should be noted that any character, including the character such as the integer 2 previously displayed can be displayed as the second character. The second character displayed on the display screen 16 will be displaced from the position that the first character was displayed due to the change in the voltage potential between the first deflection plate 50 and the second deflection plate 52. The amount of displacement is proportional to the voltage change. Consequently, if it is desired to display three characters on the display screen 16, and the potential on the second deflection plate 52 is varied between 1,100 volts and 900 volts, the deflection voltage would be stepwise decreased in 100 volt steps.

The above described operations for displaying the first two characters, 2 and 4, is repeated to display any subsequent characters, such as the number 6. As many characters can be displayed as it is desired to display on the display screen 16, within the limits of the size of particular display screen 16 and the number of enclosures 30. It will be appreciated that the display screen 16 may include a phosphor with characteristics of retaining images on the screen for an extended period of time so that a plurality of characters, such as the number 246, will be simultaneously displayed on the surface of the screen.

Referring now to FIG. 2 and FIG. 3, FIG. 2 is a block diagram of a typical electrical circuitry associated with the display tube of FIG. 1. FIG. 3 is a timing diagram of electrical voltages associated with the block diagram of FIG. 2. In FIG. 2, there is shown a clock 100 that provides a series of accurately timed pulses for synchronization of the electrical operations of the electrical circuitry. The timing pulses have a frequency related to a frequency at which the plurality of characters 18 (illustrated in FIG. 1) are displayed on the display screen 16 (FIG. 1).

A ring counter and control 102 is coupled to receive the clock signals from the clock generator 100 and to provide a count on a cyclic basis to a particular value, such as the value 3 for the example shown in FIG. 1. Every time that the counter reaches the particular count such as the count of 3, it introduces a pulse to an and" network 106. This causes a clock pulse from the generator 100 to pass through the and network 106 after the clock pulse has been delayed for a particular period of time by a delay line 104. The delayed clock pulse passing through the and network 106 triggers a monostable multi-vibrator 108. The resultant pulse from the multivibrator 108 constitutes a reset pulse which is applied to the second deflection plate 52 to provide a voltage having an amplitude equal to the maximum voltage to be applied to the second deflection plate 52. For example, as described above, the maximum voltage applied to the second deflection plate 52 can be 1,100 volts as compared to a voltage of 900 volts which is constantly being applied to the first deflection plate 50. In this way, the stream of electrons passing through one of the apertures 44 in the plate 42 is deflected to a position on the screen 16 closest to the deflection plate 52.

The ring counter 102 is connected to indicate the count at each instant on a recycling basis. For example,

in the example in FIG. 1, the ring counter provides progressive indications of the successive digits 1, 2 and 3 on a cyclic basis in accordance with the introduction of progressive clock signals to the ring counter. Separate lines are provided for indicating the count 1 to an and network 110, the count 2 to an and network 112 and the count 3" to an and network 114.

Each of the and networks 110, 112 and 114 also receives the signals from a monostable multivibrator 118, which is triggered by the clock signals from the clock generator 100. The monostable multivibrator 118 may be constructed to provide a slight delay before it becomes triggered but this delay is less than that provided by the line 104. The and network is fur ther connected to an input designated as Data Group 1, which represents the indiction, such as the integer 2 in the example of FIG. 1, to be provided on the screen 16 at the first position. The and" network 112 is connected to an input designated as Data Group 2, which represents the indications, such as the integer 4 in the example of FIG. 1, to be provided on the screen 16 at the second position. Similarly, the and" network 114 is connected to an input designated as Data Group 3, which represents the indication, such as the integer 6" in the example of FIG. 1, to be provided on the screen 16 at the third position. Actually, the indications such as those from the Data Group 1", Data Group 2 and Data Group 3 may be a plurality of indications on a plurality of lines, which indications digitally represent in binary form integers such as the decimal integers 2, 4 and 6" in the example shown in FIG. 1.

When the counter 102 has an indication of l in each count cycle, it activates the and network 110 for a period of time after the clock pulse from the generator 100. This period of time is dependent upon the time length of the pulse provided by the monostable multivibrator 118. This causes the binary indications from Data Group 1 to pass through the and network 110 to a decoder 120. The decoder decodes the digital indications from Data Group 1" and activates a particular one of the enclosures 30 dependent upon the digital indications from Data Group 1. This corresponds to the integer 2 in the example shown in FIG. 1.

Similarly, the and network 112 becomes activated upon a digital count of 2 in the counter 102 and upon the introduction of a pulse from the multivibrator 118. When the and" network 112 becomes activated, it passes to the decoder 120 the digital indications from Data Group 2" such that a particular one of the enclosures 30 becomes energized. In the example of FIG. 1, the enclosure 30 providing an indication of the integer 4 becomes energized.

When the count from the counter 102 provides an indication of a count of 3, and and network 114 becomes energized upon the introduction of a pulse from the multivibrator 118. When the and" network 114 becomes activated, it passes to the decoder 120 the signals from Data Group 3. In this way, one of the enclosures 30 becomes energized in accordance with the digital indications provided by Data Group 3. In the example shown in FIG. 1, the enclosure 30 providing an indication of the integer 6 becomes energized when the and" network 114 becomes activated.

Everytime that a clock pulse is produced by the clock generator 100, it is delayed by a delay line 122 for a particular period of time. This particular period of time is greater than the length of the pulses produced by the multivibrator 118 but less than the period of time between two successive cloek pulses and approximately the period of time provided by the delay line 104. The delayed clock signals from the line 122 are then introduced to a monostable multivibrator 124 which produces a pulse for a greater period of time than the length of the clock pulse. The pulses from the multivibrator 124 pass through an and network 126 which is also connected to the counter 102 to pass all of the pulses from the multivibrator 124 except for those which occur when a reset pulse is being introduced to the capacitor 68. The pulses passing through the and network 126 are then introduced to the capacitor 68 in FIG. 1 to bleed a particular amount of charge from the capacitor. By bleeding a particular amount of charge from the capacitor 68, the electron stream passing to the screen 16 in FIG. 1 becomes deflected to an individual one of the positions on the screen, such as the positions represented by the numerals 2", 4 and 6 in FIG. 1.

The clock pulses from the generator 100 are illustrated at 150 in FIG. 3. The signals produced by the monostable multivibrator 118 in FIG. 2 are illustrated at 152 in FIG. 3. The signals produced by the monostable multivibrator 124 are illustrated at 154 in FIG. 3 and the signals produced by the monostable multivibrator 108-are illustrated at 156 in FIG. 3. As will be seen, the pulses 152 are produced slightly after the clock pulses 150 to activate the particular enclosures 130 for the indication of the successive digits on the screen 16. The pulses 154 are produced after the pulses 152 to shift the position of indication on the screen 16 for each successive integer. However, one of the pulses 154 is not produced when an integer is being indicated in the last position on the screen 16. Instead, one of the pulses 156 is produced to reset the indication on the screen 16 to the first position so that a new cycle can be initiated.

Although this application has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which will be apparent to persons skilled in the art. For example, the invention may be used with other types of display tubes than those described above in which a separate electron gun is provided for each individual character to be displayed. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

I claim:

1. A display tube for selectively providing a visual display of a plurality of characters, comprising:

an envelope having a fluorescent coating display screen on one end,

first means disposed within the envelope for providing selected streams of electrons, the first means being coupled to receive control signals for selectively providing individual ones of the selected streams of electrons in response to the received control signal;

a mask disposed within the envelope between the display screen on the envelope and the first means, the mask having a plurality of displaced apertures in the form of selected characters to be displayed on the display screen, individual ones of the plurality of displaced apertures being in alignment with individual ones of the selected streams of electrons;

deflection means disposed between the display screen and mask, the deflection means being responsive to a multi-amplitude voltage signal for selectively deflecting the selected streams of electrons in a particular direction in accordance with the particular level of the multi-amplitude voltage signal; and

control means disposed within the envelope in alignment with at least one of the selected streams of electrons, the control means being coupled electrically to the deflection means for selectively changing the amplitude voltage levels in response to the stream of electrons for causing selected characters to be displaced simultaneously at different positions on the display screen.

2. The display tube of claim 1 wherein the deflection means includes at least one electrode.

3. The display tube of claim 1 wherein the deflection means is a pair of electrodes disposed within the tube on opposite sides of the display tube for deflecting the stream of electrons in a direction substantially parallel to the plane passing through the electrodes.

4. A display tube for selectively providing an visual display of a plurality of characters, comprising:

an envelope having a fluorescent coating display screen on one end,

a plurality of electron sources located within the envelope opposite the display screen for providing a plurality of electron streams, each of the sources being coupled to receive control signals for selectively providing electron streams in response to the received control signal;

a mask disposed within the envelope between the display screen on the envelope and the plurality of electron sources, the mask having a plurality of displaced apertures in the form of selected characters to be displayed on the display screen, individual ones of the plurality of displaced apertures being in alignment with individual ones of the plurality of electron sources;

deflection means disposed between the display screen and the mask, the deflection means being responsive to a multiamplitude voltage signal for selectively deflecting the electron streams in a particular direction in accordance with the particular level of the multi-amplitude voltage signal; and

control means disposed within the envelope in alignment with at least one of the selected streams of electrons, the control means being coupled electrically to the deflection means for selectively changing the amplitude voltage levels in response to the stream of electrons for causing selected characters to be displaced simultaneously at different positions on the display screen.

5. The display tube of claim 4 and further including means for storing electrical energy, the means for storing electrical energy being coupled electrically to the control means to receive a set signal having a particular amplitude and to receive the electrons impinging on the control means to vary the particular amplitude of the signal stored by the means for storing electrical en- 6. The display tube of claim 5 wherein the means for storing is a capacitor.

7. A display tube for selectively providing a visual display of a plurality of characters, comprising:

an envelope having a fluorescent coating display screen on one end,

first means disposed within the screen for providing selected streams of electrons toward the display screen, the first means being coupled to receive control signals for selectively providing individual ones of the selected streams of electrons in response to the received control signal;

a mask disposed within the screen between the dis play screen on the envelope and the first means, the mask having a plurality of displaced apertures in the form of selected characters to be displaced on the display screen, individual ones of the plurality of displaced apertures being in alignment with individual ones of the selected streams of electrons to shape the individual stream of electrons;

deflection means disposed between the display screen and the mask, the deflection means being responsive to a voltage signal for selectively deflecting the selected streams of electrons in a particular direction in accordance with the particular level of the voltage signal;

control means disposed within the screen in align ment with at least one of the selected streams of electrons to receive the selected stream of electrons;

means for storing electrical energy, the storing means being coupled to the control means and to the deflection means to introduce the voltage on the storing means to the deflection means and to receive the energy passing to the control means for varying the voltage across the storing means and the voltage introduced to the deflection means,

means coupled to the storing means to introduce periodically a set signal to the storing means for providing a voltage signal having a particular amplitude related to the amplitude of the set signal; and

means for obtaining an alternate direction of streams of electrons toward the mask and toward the control means to obtain a display of individual characters in displaced relationship to the display screen.

8. In combination for selectively providing a visual display of a plurality of characters,

an envelope having a fluorescent coating display screen on one end,

first means disposed within the envelope for directing streams of electrons in individual shapes toward the screen to provide a display of individual characters on' the screen,

second means disposed within the envelope and responsive to progressive voltages for selectively defleeting the streams of electrons to progressive positions on the screen in accordance with the introduction of the progressive voltages to the second means, and

means disposed within the envelope and operatively coupled to the second means and responsive to the formation of successive streams of electrons in the individual shapes for obtaining the production of the progressive voltages for introduction to the second means in accordance with the formation of such successive streams of electrons.

9. The combination set forth in claim 8, wherein,

the second means include a pair of deflection plates disposed within the envelope between the display screen and the first means and wherein the progressive deflection of the individual streams of elec trons to the different positions on the screen is dependent upon the voltage difference between the pair of deflection plates.

10. In combination for selectively providing a visual display of a plurality of characters,

an envelope,

first means disposed within the envelope for directing toward a particular position in the envelope individual streams of electrons having characteristics representative of individual characters,

second means disposed within the envelope in displaced relationship to the first means and responsive to particular voltages for deflecting the individual streams of electrons from the particular po sition in accordance with the characteristics of the particular voltages,

the envelope being constructed to provide visual indications of the characters represented by the individual streams of electrodes at the position at which the individual streams of electrons reach the envelope,

third means disposed within the envelope for producing second streams of electrons for a particular period of time after each direction of an individual stream of electrons by the first means, and

fourth means disposed within the envelope and responsive to each stream of electrons from the third means and progressively coupled to the second means for progressively changing the voltages applied to the second means in accordance with the production of each such stream of electrons.

11. The combination set forth in claim 10, including first circuit means operatively coupled to the first means for obtaining a sequential production by the first means of the individual streams of electrons with characteristics representative of individual characters, and

second circuit means operatively coupled to the third means and responsive to each production of the individual streams of electrons by the first means for obtaining the production of the second stream of electrons by the third means.

12. The combination set forth in claim 11, including,

third circuit means for operating upon the first circuit means to obtain the production of each individual stream of electrons by the first means only after the production of the second stream of electrons by the third means, and

fourth circuit means for operating upon the second circuit means to obtain the production of the second stream of electrons by the third means only after the production of each individual stream of electrons by the first means.

13. ln combination for selectively providing a visual display of a plurality of characters,

an envelope having a display screen constructed at one end to respond to streams of electrons to provide a visual display dependent upon the shape of the electron streams;

first means disposed within the envelope for directing individual streams of electrons in individual shapes toward the screen to obtain a visual display of individual characters on the display screen,

second means disposed within the envelope for deflecting the individual streams of electrons in accordance with progressive voltages applied to the second means,

third means disposed within the envelope and responsive to each formation of an individual stream of electrons for obtaining the production of a progressive voltage for introduction to the second means, and

circuit means operatively coupled to the first and third means for alternately obtaining successive productions of individual streams of electrons in representation of successive characters and for alternately obtaining the production of the progressive voltages in accordance with the successive productions of the individual streams of electrons.

14. The combination set forth in claim 13, wherein the second means include a pair of spaced plates disposed within the envelope and the third means include an electrode disposed within the the envelope for receiving streams of electrons and a capacitor reponsive to the streams of electrons received by the electrode and having a variable charge in accordance with such reception of electrons by the electrode for providing the progressive voltage for introduction to the second means.

15. In combination for selectively providing a visual display of a plurality of characters,

an envelope having a display face constructed to display individual characters in accordance with the shape of individual streams of electrons directed toward the display face,

first means within the envelope for individually directing toward a first position in the envelope individual streams of electrons shaped to simulate individual characters,

second means within the envelope, the second means being responsive to an applied voltage for deflecting the individual streams of electrons to individual positions on the screen in accordance with the characteristics of such applied voltage,

third means operatively coupled to the second means and having a variable charge for applying a voltage to the second means in accordance with the variable charge to control the deflection of the individual stream of electrons,

fourth means disposed within the envelope for providing additional streams of electrons,

fifth means operatively coupled to the third means and disposed within the envelope to receive the additional stream" of electrons from the fourth means and to vary the charge in the third means in accor dance with such streams, and

sixth means operatively coupled to the first and fourth means for alternately obtaining a flow of the individual streams of electrons and the additional streams of electrons.

16. The combination set forth in claim 15, including,

seventh means operatively coupled to the third means and responsive to each display of the individual characters in particular positions on the display face of the envelope for charging the third means to a particular value for initiating a new display of the individual characters in the particular positions on the display face of the envelope.

17. The combination set forth in claim 16 wherein,

the first means includes a plurality of electron guns each energized to indicate an individual character and the first means further includes a mask having a plurality of apertures each associated with an individual one of the electron guns in the plurality and each having an individual shape to pass the stream of electrons from its associated gun in an individual configuration to the display face of the envelope.

18. The combination set forth in claim 16 wherein the third means includes a capacitor and wherein the fourth means is operative to change the charge of the capacitor by a particular amount every time that an individual stream of electrons is directed by the first means toward the display face of the envelope.

19. The combination set forth in claim 13 wherein the first means includes a plurality of electron guns each energized to indicate an individual character and the first means further includes a mask having a plurality of apertures each associated with an individual one of the electron guns in the plurality of each having an individual shape to pass the stream of electrons from its associated gun in an individual configuration to the display face of the envelope. 

1. A display tube for selectively providing a visual display of a plurality of characters, comprising: an envelope having a fluorescent coating display screen on one end, first means disposed within the envelope for providing selected streams of electrons, the first means being coupled to receive control signals for selectively providing individual ones of the selected streams of electrons in response to the received control signal; a mask disposed within the envelope between the display screen on the envelope and the first means, the mask having a plurality of displaced apertures in the form of selected characters to be displayed on the display screen, individual ones of the plurality of displaced apertures being in alignment with individual ones of the selected streams of electrons; deflection means disposed between the display screen and mask, the deflection means being responsive to a multi-amplitude voltage signal for selectively deflecting the selected streams of electrons in a particular direction in accordance with the particular level of the multi-amplitude voltage signal; and control means disposed within the envelope in alignment with at least one of the selected streams of electrons, the control means being coupled electrically to the deflection means for selectively changing the amplitude voltage levels in response to the stream of electrons for causing selected characters to be displaced simultaneously at different positions on the display screen.
 2. The display tube of claim 1 wherein the deflection means includes at least one electrode.
 3. The display tube of claim 1 wherein the deflection means is a pair of electrodes disposed within the tube on opposite sides of the display tube for deflecting the stream of electrons in a direction substantially parallel to the plane passing through the electrodes.
 4. A display tube for selectively providing a visual display of a plurality of characters, comprising: an envelope having a fluorescent coating display screen on one end, a plurality of electron sources located within the envelope opposite the display screen for providing a plurality of electron streams, each of the sources being coupled to receive control signals for selectively providing electron streams in response to the received control signal; a mask disposed within the envelope between the display screen on the envelope and the plurality of electron sources, the mask having a plurality of displaced apertures in the form of selected characters to be displayed on the display screen, individual ones of the plurality of displaced apertures being in alignment with individual ones of the plurality of electron sources; deflection means disposed between the display screen and the mask, the deflection means being responsive to a multiamplitude voltage signal for selectively deflecting the electron streams in a particular direction in accordance with the particular level of the multi-amplitude voltage signal; and control means disposed within the envelope in alignment with at least one of the selected streams of electrons, the control means being coupled electrically to the deflection means for selectively changing the amplitude voltage levels in response to the stream of electrons for causiNg selected characters to be displaced simultaneously at different positions on the display screen.
 5. The display tube of claim 4 and further including means for storing electrical energy, the means for storing electrical energy being coupled electrically to the control means to receive a set signal having a particular amplitude and to receive the electrons impinging on the control means to vary the particular amplitude of the signal stored by the means for storing electrical energy.
 6. The display tube of claim 5 wherein the means for storing is a capacitor.
 7. A display tube for selectively providing a visual display of a plurality of characters, comprising: an envelope having a fluorescent coating display screen on one end, first means disposed within the screen for providing selected streams of electrons toward the display screen, the first means being coupled to receive control signals for selectively providing individual ones of the selected streams of electrons in response to the received control signal; a mask disposed within the screen between the display screen on the envelope and the first means, the mask having a plurality of displaced apertures in the form of selected characters to be displayed on the display screen, individual ones of the plurality of displaced apertures being in alignment with individual ones of the selected streams of electrons to shape the individual stream of electrons; deflection means disposed between the display screen and the mask, the deflection means being responsive to a voltage signal for selectively deflecting the selected streams of electrons in a particular direction in accordance with the particular level of the voltage signal; control means disposed within the screen in alignment with at least one of the selected streams of electrons to receive the selected stream of electrons; means for storing electrical energy, the storing means being coupled to the control means and to the deflection means to introduce the voltage on the storing means to the deflection means and to receive the energy passing to the control means for varying the voltage across the storing means and the voltage introduced to the deflection means, means coupled to the storing means to introduce periodically a set signal to the storing means for providing a voltage signal having a particular amplitude related to the amplitude of the set signal; and means for obtaining an alternate direction of streams of electrons toward the mask and toward the control means to obtain a display of individual characters in displaced relationship to the display screen.
 8. In combination for selectively providing a visual display of a plurality of characters, an envelope having a fluorescent coating display screen on one end, first means disposed within the envelope for directing streams of electrons in individual shapes toward the screen to provide a display of individual characters on the screen, second means disposed within the envelope and responsive to progressive voltages for selectively deflecting the streams of electrons to progressive positions on the screen in accordance with the introduction of the progressive voltages to the second means, and means disposed within the envelope and operatively coupled to the second means and responsive to the formation of successive streams of electrons in the individual shapes for obtaining the production of the progressive voltages for introduction to the second means in accordance with the formation of such successive streams of electrons.
 9. The combination set forth in claim 8, wherein, the second means include a pair of deflection plates disposed within the envelope between the display screen and the first means and wherein the progressive deflection of the individual streams of electrons to the different positions on the screen is dependent upon the voltage difference between the pair of deflection plates.
 10. In combination for selectively providIng a visual display of a plurality of characters, an envelope, first means disposed within the envelope for directing toward a particular position in the envelope individual streams of electrons having characteristics representative of individual characters, second means disposed within the envelope in displaced relationship to the first means and responsive to particular voltages for deflecting the individual streams of electrons from the particular position in accordance with the characteristics of the particular voltages, the envelope being constructed to provide visual indications of the characters represented by the individual streams of electrodes at the position at which the individual streams of electrons reach the envelope, third means disposed within the envelope for producing second streams of electrons for a particular period of time after each direction of an individual stream of electrons by the first means, and fourth means disposed within the envelope and responsive to each stream of electrons from the third means and operatively coupled to the second means for progressively changing the voltages applied to the second means in accordance with the production of each such stream of electrons.
 11. The combination set forth in claim 10, including first circuit means operatively coupled to the first means for obtaining a sequential production by the first means of the individual streams of electrons with characteristics representative of individual characters, and second circuit means operatively coupled to the third means and responsive to each production of the individual streams of electrons by the first means for obtaining the production of the second stream of electrons by the third means.
 12. The combination set forth in claim 11, including, third circuit means for operating upon the first circuit means to obtain the production of each individual stream of electrons by the first means only after the production of the second stream of electrons by the third means, and fourth circuit means for operating upon the second circuit means to obtain the production of the second stream of electrons by the third means only after the production of each individual stream of electrons by the first means.
 13. In combination for selectively providing a visual display of a plurality of characters, an envelope having a display screen constructed at one end to respond to streams of electrons to provide a visual display dependent upon the shape of the electron streams, first means disposed within the envelope for directing individual streams of electrons in individual shapes toward the screen to obtain a visual display of individual characters on the display screen, second means disposed within the envelope for deflecting the individual streams of electrons in accordance with progressive voltages applied to the second means, third means disposed within the envelope and responsive to each formation of an individual stream of electrons for obtaining the production of a progressive voltage for introduction to the second means, and circuit means operatively coupled to the first and third means for alternately obtaining successive productions of individual streams of electrons in representation of successive characters and for alternately obtaining the production of the progressive voltages in accordance with the successive productions of the individual streams of electrons.
 14. The combination set forth in claim 13, wherein the second means include a pair of spaced plates disposed within the envelope and the third means include an electrode disposed within the envelope for receiving streams of electrons and a capacitor reponsive to the streams of electrons received by the electrode and having a variable charge in accordance with such reception of electrons by the electrode for providing the progressive voltage for introduction to the second means.
 15. In combination for selectively proviDing a visual display of a plurality of characters, an envelope having a display face constructed to display individual characters in accordance with the shape of individual streams of electrons directed toward the display face, first means within the envelope for individually directing toward a first position in the envelope individual streams of electrons shaped to simulate individual characters, second means within the envelope, the second means being responsive to an applied voltage for deflecting the individual streams of electrons to individual positions on the screen in accordance with the characteristics of such applied voltage, third means operatively coupled to the second means and having a variable charge for applying a voltage to the second means in accordance with the variable charge to control the deflection of the individual stream of electrons, fourth means disposed within the envelope for providing additional streams of electrons, fifth means operatively coupled to the third means and disposed within the envelope to receive the additional stream of electrons from the fourth means and to vary the charge in the third means in accordance with such streams, and sixth means operatively coupled to the first and fourth means for alternately obtaining a flow of the individual streams of electrons and the additional streams of electrons.
 16. The combination set forth in claim 15, including, seventh means operatively coupled to the third means and responsive to each display of the individual characters in particular positions on the display face of the envelope for charging the third means to a particular value for initiating a new display of the individual characters in the particular positions on the display face of the envelope.
 17. The combination set forth in claim 16 wherein, the first means includes a plurality of electron guns each energized to indicate an individual character and the first means further includes a mask having a plurality of apertures each associated with an individual one of the electron guns in the plurality and each having an individual shape to pass the stream of electrons from its associated gun in an individual configuration to the display face of the envelope.
 18. The combination set forth in claim 16 wherein the third means includes a capacitor and wherein the fourth means is operative to change the charge of the capacitor by a particular amount every time that an individual stream of electrons is directed by the first means toward the display face of the envelope.
 19. The combination set forth in claim 13 wherein the first means includes a plurality of electron guns each energized to indicate an individual character and the first means further includes a mask having a plurality of apertures each associated with an individual one of the electron guns in the plurality of each having an individual shape to pass the stream of electrons from its associated gun in an individual configuration to the display face of the envelope. 